1. Field of the Invention
The present invention relates generally to a method and apparatus for manufacturing rupture disks, and more particularly, but not by way of limitation, to an improved method and apparatus for manufacturing rupture disks containing one or more scores or perforations from sheet metal sections.
2. Description of the Prior Art
Many fluid pressure relief devices of the rupturable type have been developed and used heretofore. Commonly, such rupturable pressure relief devices include a rupture disk supported between a pair of supporting members or flanges which are in turn connected to a relief connection in a vessel or system containing fluid pressure. When the fluid pressure within the vessel or system exceeds the design rupture pressure of the disk, rupture occurs causing excess fluid pressure to be relieved from the vessel or system.
Various types of rupture disks and rupture disk assemblies have been developed and used which fall within three general categories, i.e., those that rupture in tension known as "conventional" rupture disks, those that reverse and then rupture known as "reverse buckling" rupture disks and composites of both the conventional and reverse buckling types. Composite rupture disk assemblies generally include one or more rupture disks combined with one or more perforated members such as vacuum supports, protection members, members which tear or rupture when a primary rupture disk ruptures, etc. While some rupture disks and composite assemblies are flat, most include an annular flat flange portion to facilitate clamping between supporting members or flanges connected to a concave-convex dome portion which ruptures when excess fluid pressure is exerted on the disk. In the operation of a reverse buckling rupture disk, the fluid pressure is exerted on the convex side of the dome portion of disk, and upon failure, the dome portion reverses and then ruptures. Fluid pressure is exerted on the concave side of conventional rupture disks and the disks rupture in tension.
Metal rupture disks of both the reverse buckling type and conventional type have heretofore included one or more scores on a surface of the concave-convex portion which create lines of weakness so that upon rupture of the disk, the concave-convex portion tears along the lines of weakness and opens with little or no fragmentation of the metal. Various methods of manufacturing scored rupture disks have heretofore been developed. For example, a method of manufacturing reverse buckling scored disks is disclosed in U.S. Pat. No. 3,921,556 issued Nov. 25, 1975 and assigned to the assignee of the present invention. While such method as well as other methods have been used successfully for manufacturing scored reverse buckling rupture disks, because of deformation and stresses which are produced in the disks, a number of reforming and annealing steps have heretofore been required to produce rupture disks having desired operational characteristics. Generally, in all of the heretofore used methods of manufacturing scored or perforated rupture disks, the stresses and deformation produced when forming the scores or perforations have brought about less than optimum operational characteristics or require additional manufacturing steps.
By the present invention an improved method and automated apparatus for carrying out the method are provided for manufacturing scored and perforated rupture disks of the conventional, reverse buckling and composite types wherein deformation and stresses in the disks due to the manufacturing process are reduced and all or part of the time-consuming and expensive reforming and annealing procedures previously required are eliminated.